The use of saunas to promote the formation of perspiration (sweating) for its therapeutic effects, is well known. However, the use of saunas relying primarily on the body deep absorption of infrared radiation, is not known. While the provision of a sauna cabinet per individual is known, such individual cabinets have not been compact or portable.
The use of infrared heaters throughout history is well known. Humans first warmed themselves with campfires, later with fireplaces, and now with radiant floors and infrared sauna rooms. However, heretofore when using any infrared source greatly warmer than room temperature, it was difficult to protect a user from touching the hot surface (and experiencing pain or burning) without disadvantageously shielding the heat source in the process. Therefore the emitting surface was either placed far away from the user or had a bulky screen placed around it. In either case, the heater could not safely be in close proximity to the user.